I inhaled paint mist how longdoes it take my lungs to clear out the mist?

Varies: Are you having trouble breathing? Coughing that won't go away? Sometimes paint fumes like any chemical inhalation can cause irritation. If no symptoms, I wouldn't worry about it. I don't think anyone can give you any definitive answer on how long it takes to 'go away.' If you have no symptoms you're going to be ok.

Difficult to say: It depends on the particular, chemicals, size of the inhalant vapor particles, amount of inhaled vapor/mist and the health of your lungs. Without more information, it's difficult to say.